A. Field of Invention
This invention relates to the art of spreaders and more specifically to methods and apparatuses related to an electric interlock that prevents a door from being opened unless operation of the spreader has been stopped.
B. Description of the Related Art
The spreading of materials, such as sand, salt, cinders and other granular material, is a common practice to maintain roads, drive ways, parking lots, and other ground surfaces. Typically, a material spreading device (often referred to as a “material spreader” or simply as a “spreader”) is mounted to the rear of a vehicle. The vehicle is then driven along the ground surface that needs maintained and the granular material is released or spread onto the ground surface.
Typically, there are one or more doors or covers that provide access to the inside of the spreader for maintenance purposes. If such doors were to be opened during operation of the spreader, however, safety concerns arise as it is possible that the operator could become injured if a component within the spreader, such as a rotating auger, was inadvertently contacted. In order to prevent such injuries spreaders may be provided with safety systems. One known safety system is a hydraulic safety system that works with the hydraulic system that provides hydraulic fluid to operate the auger. In general, the hydraulic safety system works by stopping the flow of hydraulic fluid to thereby disable the auger in the event that a door is opened during operation of the auger. While known spreader safety systems work well for their intended purposes, additions and improvements are desirable.
In particular, what is needed is a safety system that works with electric systems used in the operation of spreaders.